In the plant kingdom, many distantly related species will show convergent evolution under natural selection, for example, plants living in arid desert environments often have leaves degenerated into needles, alpine plants are mostly dwarfed into mats, etc.
, however, whether most morphological convergent evolution hides the convergent evolution at the molecular level is still an unsolved mystery
The heteromorphic flower column is one of the well-known polymorphic phenomena of flowers, which is manifested by a high degree of interaction matching between the pistils and the stamens, that is, interactive dioecious ectopy
The polymorphism of this flower is conducive to promoting precise pollination of plants and avoiding male and female interference, while the accompanying self-inbred incompatibility system also helps to ensure crosscrossing to avoid inbreeding decline, which is of great significance
in promoting the diversity and differentiation of plants.
Heteromorphic flower column is ubiquitous in 28 families and 199 genera of angiosperms, and is a typical case
of convergent evolution in morphology and function in the plant world.
Therefore, it is of great significance to explore whether molecular level convergent evolution occurs in heterogeneous cylindrical plants, which helps us understand the constraint mechanism of the evolution of the plant's reproductive organ, the flower.
The research team of Zhang Dianxiang of the South China Botanical Garden of the Chinese Academy of Sciences took Gelsemium elegans as the research object, combined with genomics, morphology, reproductive biology and other multiple methods, and identified the supergene (S-locus) that controls the development of type II flower column in hook kiss supergene) and its 4 constituent genes, and systematically elucidating its genetic structure and evolution
The results showed that in all the studied type II flower column plants, the type II flower column supergenes were all hemizygous structures, indicating that the type II flower column related genes have a strong genetic structure convergence evolution
In this study, it was further found that the genes controlling the length of the flower column in hook snout neutralization and primrose both originated from the replication of the same gene (), indicating that there is a gene-level convergent evolution under the morphological convergence evolution
of the heterogeneous flower column 。 The results of this study also showed that the genes controlling the length of the flower column in heterotypic cylindrical plants were involved in the brassinsterol metabolism pathway, indicating that this class of hormones played an important role
in the development and regulation of heterotypic cylindrical plants.
This discovery not only has great significance for the study of the evolution and molecular regulation mechanism of type II flower column, but also provides a new case
for the origin of "supergenes" in biological evolution.
The results were recently published in the International Journal of Botany Classics New Phytologist (IF=10.
South China Botanical Garden is the first and corresponding author, assistant researcher Zhao Zhongtao is the first author of the paper, and researcher Zhang Dianxiang is the corresponding author
Link to paper: https://nph.